Binding post



Jan. 22, 1929.

H. H. EBY

BINDING POST Filed Feb. 27, 1925 /IIIlIII/l Patented Jan. 22, 1929.

.UNITED STATES HUGH n. EBY, or rnmnnnnrnm, rEimsYLvAnrA.

BINDING ros'r.

. Application filed February 27, 1925. Serial No. 11,982.

My invention relates to binding posts for electrical apparatus designed for quick and convenient e ectrical connection.

One of the purposes of my invention is to cheapen the manufacture of binding posts in which the contact cap is not removable from the post member.

A further purpose is to enclose the operative threads of the post from exposure and in- ]ury.

A further purpose is to make the cap clamping element on a binding post fit the cylindrical portion of the post back of the threaded head of the post by inwardly extending an inner rim of the cap on to the cylindrical portion when the cap has been screwed to place over the thread.

Further purposes will appear in the specification and in the claims.

I have referred to illustrate my invention by a few orms only of a number that may be used, selecting forms that are practical, eflicient and inexpensive and which at the same time well illustrate the principles of my invention.

Figures 1 and 2 are vertical central sections through upper (cap) and lower (base) contacts respectively used in my invention but lacking the usual moulded insulation.

Figure 3 is a side elevation of the stem or post member of the complete binding post.

Figure 4 is a central vertical section, ex-

cept as to the lower contact member which is in elevation, of an assembly of post, cap and base.

Figure 4 is a fragmentary section showing a portion of the cap only, crimped or peened into retaining position. Figure 4 is a fragmentary section corresponding to the upper part of Figure 4 but omitting a stop ring shownin that figure and showing the retaining ring before it is closed to position. 9

Figure 5 is a bottom plan view of Figure 2.

Figure 6 is a broken side elevation and partial section showing a slightly different stem and contact member and with a molded cover insulating the cap and preventing removal of the stem.

Figure 7 is a section taken upon line 77 of Figure 6 looking in the direction of the arrows.

Figure 8 is a side elevation of an assembled binding post, embodying my invention.

Figure 9 1s a side elevation partly in verti- 0911 section of a lower contact-member and I cover similar to that in Figure 8.

Figure 10 is a bottom plan View of Figure 9.

Figure 11 is a fragmentary section showing a form in which the-lower contact member is integral with the stem.

In the drawings similar numerals indicate like parts.

Describing in illustration and not in limitation and referring to the drawings This application is in large measure carved out of my application in the United States for binding posts, filed January 4, 1924, Serial No. 684,290, and therefore a continuation of it and of its parent application for electrical binding posts filed February 24, 1922, Serial No. 534,183.

The stem 15 of my binding post is shown as threaded at 16 for convenient nut attachment (see Figure 8) to any suitable support. It is provided with lower contact member 17 which may be integral with the stem, as in Figure 11, or may be secured to it by any suitable means of which the simplest is by screwing the member upon the threads. The member, when separate may be sweatedupon the thread or may be otherwise attached by forcingit on lengthwise of the stem or by squeezing it transversely to the stem. 9

The diameter is shown as relatively reduced at 19 below that of the contact face20, which in this case is made the upper face of a flange 21 for the purpose of providing relatively large contact surface and with the intention of filling in the portion below the flange with a molded composition giving de sirable finish and having also insulation value. The outside of the contact member is roughened to hold this to the best advantage. 95

Obviously when it is not desired to use this molded material the metal will fill out the full contour and the same size of contact surface will be obtained without need of any flanges.

The filling of the lower portion at 22 beneath the flange, where a flange is used, gives a very neat appearance without reducing the contact surface. i

This finish material is ordinarily an insum5 lating composition. It is secured to the lower contact member against longitudinal movement by grooving the latter as at 23 to permit interlocking of p the covering material with the contact member. Rotation may 7 be stopped in any suitable way of which I show one, I y flattening one, side as dotted at 20 (Figure i The lower edge of the contact member extends below the base 22, as at 24, and is roughened in any suitable manner, as by the teeth shown, so as to bite into the surface of the support to which the binding post is to be applied, preventin turning of the binding. post and giving a rmer and more rigid seat to the post. The under side of the contact member is also recessed at 25 (Figure 9) for the purposeof making the roughening more effective and, when the contact member is in one piece and is soldered on the post to facilitate application of the solder at the apex of the recess at 26.

The binding post may be held in position against the support by nuts 27 28. 'Between the "nuts are located washers 29 so that the nut 27 may be fastened against the back or under side of the support and the nut 28 may be used for the double purpose of clamping the conductor between the washers 29 and of acting as a lock nut for the nut 27.

Above the contact surface 20 the stem or post is formed of reduced section, preferably as a cylinder 30 which is apertured at 31 close to the surface 20 to permit passage of the conductor to be clamped. The stem maybe encircled by the conductor if desired.

The c lindrical part 30 extends far enough ong the length of the post to provide for any required 0 ening between the clamping surface 20 an the clamping surface 32 upon the bottom part 33 of the upper contact or nut 34. Where a molded cover is to be used as shown, instead of making the cap of full metal this lower part may appear as a flange to give a larger contact surface than would otherwise be permissible with the same amount ofmetal. I alsoprovide for an inwardly directed stop abutment 35 be tween the surface 32 and th thread 36 upon the upper end of the stem. e bulk of this thread 36 is of outside diameter appreciably larger than that of the cylindrical portion of the stemso as to provide for a shoulder 37 which engages with the abutment 35 to limit the upper position of the cap with respect to the stem. Cap threads 38 may extend, initially clear to ca bottom.

In this form 0 Figures 1-4 the upper end of the cap is closed at 39 and the stem is intended to be passed into the cap through the lower open end, the abutment 35, however formed, not being extended toward the cylindrical surface until the cap is in place covering the thread 36 of the stem and having its lower end overlapping a part of the cylindrical portion 30. Initially the abutment 35 preferably extends axially as shown in Figure 1, and when the cap is in place over the head of the stem, as above; the metal is extended inwardly toward the cylindrical surface to form an abutment (as by swaging',

bending, peening, spinning or by any other become wedged withinthe space between this inward extension and the cylindrical portion.

In Figure 4 an enlarged lower opening in the ca is closed as at 4.0 by forcing a supplement abutment (which 1s here shown as a ring) 41 into the enlarged opening and swaging, pressing or spinning the metal of the abutment against the supplemental abutment. In this case the abutment by which the supplemental abutment is held-in place should be forced-in so as to leave a flat lower contact surface. However it, will be seen that there is not the same need of having the main abutment extend to a diameter smaller than the thread and hence of having it pressed, spun or ot erwise forced inwardly) as if it were the only abutment, since the supplemental abutment can be sprung into place to extend inwardly much further than the main abutment.

As thus constructed in any of the forms the cap contact is given a range of movement suflicient for proper gripping of any conductor placed between the two contact faces. It provides a large surface of'contact and grips equally a straight conductor passing through the opening or of a bent conductor encircling the stem wholly or in part. Bemoval of the cap from the stem is prevented, longitudinal movement is limited to any predetermined range desired, and the base of the cap member may snugly fit the cy1indrioal portion of the stem so that there are no exposed threads nor any danger of a fine conductor catching between the cap and cylindrical portion.

I prefer to stop the. thread in the cap before the abutment 35 is reached and enlarge the lower interior in order that there may be a clear cut and sharp stop as distinguished from a less desirable wedging of the thread of the stem against an inwardly tapering cap thread.

' -Where the cap screws on from above and is as crim-ped or swaged at 43. This would of course be done, as in Figure 4', after the threaded stem had been screwed into the cap. In each of these forms the cap abutment is intended to take the thrust direct1y. No ring need be used.

\Vhatever the form of stop provided within the cap to prevent relative axial movement of the stem with respect to the cap so as to retain the cap, whether the stop upon the cap be the main abutment itself or a ring or other stop, and whether the stop engage portions of the thread (Figure 4, or 4) or independent shoulder structure earned by the stem, (Figure 6), accidental removal of the cap is prevented.

The opening 31 may be of any shape desired and slighteplay between the thread 36 and the interior thread 38 may be provided to permit slight canting of the surface 32 with respect to the conductor to be engaged where taper or irregularity of the conductor make this canting desirable in order to insure good contact along the entire length of this part of the conductor.

The comparatively close sliding contact of the cylindrical portion 30 upon the stem with the walls of the cap opening through which it passes protects against catching and shearing of the fine wires and adds to the appearance of the post.

Where the lower contact is separate from the stem, sweating of the lower contact to the stem provides better electrical conductivity. Atthe same time this lower contact is stiffened and is prevented from shifting from its preferred posit-ion level with the bottom of the opening 81.

It will be obvious that part or all of the benefit of my invention may be secured by the use of other appliances and constructions than those shown, whether to suit special needs, to meet the views or whims of others skilled in the art or to avoid mere copying of the structure shown; and it is my purpose to include herein all such as fall within the reasonable spirit and scope of my invention. Having thus described my invention, what I claim as new and desire to secure by Letters Patent is 1. In the manufacture of binding posts in which each post has a cap threaded upon a head at the end of a cylindrical portion of lesser diameter than the head, the novelty which consists in inwardly extending the inner end of the cap back of the head after the cap has been screwed onso that its inner end overlaps the cylindrical portion.

2. In the manufacture of bindnig posts in which each post has a cap threaded upon a head at the end of a cylindrical stem of lesser diameter than the head, the novelty which consists in screwing the cap to a position in which its inner end overlaps the stem and in turning its inner end inwardly to fit the stem.

3. A binding post having a threaded head, a lower contact member having .a face directed toward the head, a cylindrical stem between the head and member and of less diameter than that of the head, and .a cap contact member integrallyclosed at its outer end, threaded upon the head and having its contact face inwardly extending to fit the stem between the head and lower contact member.

. 4. A. binding post having a threaded head, a lower contact member having a face directed toward the head, a cylindrical stem between the head and member and of less diameter than that of the head, a cap contact member threaded upon the head and having a counterbore at its rear end, a ring in the counterbore, and an end portion of the cap turned inwardly over the ring.

HUGH H. EBY. 

